This invention relates in general to a vehicle event data recorder that continuously monitors a vehicle""s operation and the surrounding environment and that records, for later review, automobile operating parameters provided by sensors, including audio and visual sensors, and more particularly relates to such an event recorder including a validation system for validating that output data have not been changed from the original recorded data.
The digital data recorded from a vehicle event recorder can be used as evidence of events surrounding a xe2x80x9ctriggering eventxe2x80x9d such as a traffic accident, a traffic stop by a law official, or a crime or altercation.
The veracity of the recorded evidence can be challenged. The one attacking the veracity of the recorded evidence argues that the evidence has been in the control of the offeror of the evidence and may have been altered. For example, sensor information as to the vehicle speed or acceleration, or to the time and place may have been changed as desired by the offeror.
Therefore, there has been a need for a vehicle event data recorder including a validation system, secure from tampering, that indicates if the recorded data have been changed. The evidentiary value of the validated data is thereby substantially increased.
A preferred embodiment of the invention is an event recorder mounted in a vehicle including sensors and means for recording signals from the sensors, including surrounding audio and visual information, in the time period before, during, and after a triggering event.
The recorder includes a CPU and program memory programmed to perform a validation function, such as a one-way hash function, on the captured sensor signal while transferring it to a persistent memory device so as to derive a validation value, which is also stored in an address block, such as a file, in the persistent memory device. To later verify that the data have not been tampered with, the file is operated on by the same validation function so as to derive an audit validation value, the audit validation value is compared with the validation value for equality and the outcome of the comparison is indicated. The validation function and the comparison are secure from tampering.
The captured information can be used as evidence of innocence in an accident or of a traffic violation or of unwarranted pullover, stopping or harassment by police.
Other features and many attendant advantages of the invention will become more apparent upon a reading of the following detailed description together with the drawings wherein like reference numerals refer to like parts throughout.